What is the definition of concentration in a solution?

The definition of concentration in a solution refers specifically to the amount of a substance (the solute) present in a given volume of that solution. This concept quantitatively describes how "strong" or "weak" a solution is based on the solute's presence relative to the solvent. Concentration can be expressed in various units, such as moles per liter (mol/L), grams per liter (g/L), or percentage solutions.

Understanding that concentration is not merely the volume of the solvent, the mass of solute without context, or an abstract count of moles helps clarify the precise nature of this concept. Concentration offers a measurable way to define how much of a substance is dissolved in a specific amount of solution, making it crucial in various chemical contexts where reactions depend on the ratios of reactants.